1. Field of the Invention
The present invention relates to a method and apparatus for managing a camp-on operation between subscribers in an exchange system in which a communication is performed based on personal identification information for identifying individual subscribers.
2. Prior Art
Recent exchange systems have various functions for improving the efficiency of information exchange processing. Camp-on is an example of such functions.
The camp-on is a function in which when a communication terminal A calls a communication terminal B but the latter is busy, the call from the communication terminal A is temporarily disconnected and the communication terminals A and B are called after the communication terminal B becomes free.
More specifically, when the communication terminal A calls the communication terminal B but the latter is busy, an exchange system registers terminal numbers of the communication terminals A and B. Then, the exchange system temporarily disconnects the call from the communication terminal A, and monitors the communication of the communication terminal B. Upon detection of the communication terminal B becoming free, the communication system calls the communication terminals A and B based on their terminal numbers.
The function of camp-on makes it unnecessary for the communication terminal A to perform a cumbersome task of calling plural times the communication terminal B until the end of its communication, and allows a communication to be established between the communication terminals A and B immediately after the communication terminal B becomes free.
In the above function of camp-on, which is based on the terminal numbers of the respective communication terminals, at a time point when, for instance, a subscriber on a call-receiving side changes his communication terminal of actual use by transfer, call park, etc. with his communication maintained while camp-on registration is effective, it is detected that a camp-on-registered communication terminal has become free and, therefore, that terminal not being accompanied by the subscriber is called as a camp-on operation. Also, when a subscriber on a calling side leaves his communication terminal of actual use while camp-on registration is effective, he needs to cancel the camp-on setting, which is a cumbersome task. If he fails to cancel the setting, that communication terminal is called as a camp-on operation as soon as a communication terminal on a call-receiving side becomes free, which is inefficient.